A hydrogenation alkylation catalyst and its preparation method

Abstract

This invention discloses a hydrogenation alkylation catalyst and its preparation method. The catalyst comprises a metal component and a molecular sieve, wherein the molecular sieve has an aluminum (Al) framework. [F] ) and non-framework aluminum (Al) [EF] The weight ratio of the catalyst to cyclohexylbenzene is 5.0–15.0:1. This catalyst is particularly suitable for the hydrogenation alkylation of benzene, and can improve the activity, selectivity, and stability of the hydrogenation alkylation reaction.

Description

Technical Field

[0001] This invention belongs to the technical field of catalytic chemistry and chemical engineering, and in particular relates to a hydrogenation alkylation catalyst and its preparation method. Background Technology

[0002] Cyclohexylbenzene, a product of benzene hydrogenation alkylation, can be used as a high-boiling-point solvent, a liquid crystal intermediate, and an overcharge prevention additive for lithium-ion battery electrolytes. It can also produce phenol and cyclohexanone through oxidation-decomposition reactions, making it a high-value-added chemical with market potential.

[0003] The benzene hydrogenation alkylation method is a one-step process to directly produce cyclohexylbenzene. The synthesis process is simple, green, and low-cost, and has promising applications. However, in actual reaction, the yield of cyclohexylbenzene is limited by side reactions such as deep hydrogenation and secondary alkylation.

[0004] CN114130424A discloses a hydrogenation alkylation catalyst, its preparation method, and its application. The catalyst comprises an inorganic oxide, a modified molecular sieve, and a metal component, wherein the ratio of acid center density to micropore volume of the modified molecular sieve is 1000–2000 μmol / cm³. 3 The preparation method of the modified molecular sieve includes: optimizing the ratio of acid center density to molecular sieve micropore volume through subsequent hydrothermal treatment and acid-base treatment of the basic molecular sieve. This catalyst, used in the hydrogenation alkylation reaction of benzene, exhibits good selectivity for cyclohexylbenzene and significantly improves the selectivity for dicyclohexylbenzene.

[0005] CN109772432A discloses a metal-coated catalyst for the selective hydrogenation alkylation of benzene to prepare cyclohexylbenzene, as well as its preparation and application methods. The catalyst consists of an active component, a molecular sieve, and a framework. The preparation method involves first loading the active component onto an H-type molecular sieve, performing a reduction reaction, and then introducing the molecular sieve loaded with the active component into a silica-alumina gel for crystallization. This is followed by another H-exchange and reduction reaction to obtain a metal-coated bifunctional catalyst, where the molecular sieve loaded with the active component is encapsulated within the framework. However, this method is complex, and the multiple reduction reactions increase costs.

[0006] In summary, how to synthesize molecular sieve catalysts with efficient coupling of hydrogenation and alkylation functions in a more economical way, and improve the yield of cyclohexylbenzene, is a research hotspot in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a hydrogenation alkylation catalyst and its preparation method. The catalyst of this invention, when used in the benzene hydrogenation alkylation reaction, can improve the activity of the benzene hydrogenation alkylation reaction, the selectivity of cyclohexylbenzene, and its stability.

[0008] A first aspect of the present invention provides a hydrogenation alkylation catalyst, the catalyst comprising a metal component and a molecular sieve, wherein the molecular sieve has an aluminum (Al) framework. [F] ) and non-framework aluminum (Al) [EF] The weight ratio of ) is 5.0 to 15.0:1.

[0009] In the above technical solution, preferably, the outer surface of the molecular sieve contains semi-supercage aluminum (Al). (61) ) and framework aluminum (Al) [F] The weight ratio is 0.22 to 0.50:1.

[0010] In the above technical solution, the molecular sieve has an aluminum (Al) framework. [F] ) and non-framework aluminum (Al) [EF] The weight ratio of the components is 5.0 to 15.0:1, preferably 7.0 to 11.0:1, more preferably 7.0 to 10.0:1, and more specifically, non-limiting weight ratios can be 5.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 12.0, 13.0, 14.0, 15.0, etc.

[0011] In the above technical solution, the outer surface of the molecular sieve contains semi-supercage aluminum (Al). (61) ) and framework aluminum (Al) [F] The weight ratio is 0.22 to 0.50:1, preferably 0.22 to 0.42:1, more preferably 0.25 to 0.30:1, and more specifically, non-limiting weight ratios can be 0.22, 0.23, 0.24, 0.25, 0.28, 0.30, 0.32, 0.35, 0.38, 0.40, 0.42, 0.45, 0.48, 0.50, etc.

[0012] In the above technical solution, preferably, the molecular sieve is a silica-alumina molecular sieve with a twelve-membered ring channel structure, more preferably MCM-22 molecular sieve. More preferably, the SiO2 / Al2O3 molar ratio of the molecular sieve is 15–55, more preferably 18–38.

[0013] In the above technical solution, preferably, the metal component in the catalyst is selected from at least one of Ru, Pd, and Pt.

[0014] In the above technical solution, preferably, the metal component in the catalyst accounts for 0.05% to 1.0% of the molecular sieve mass, more preferably 0.10% to 0.30% by mass fraction.

[0015] In the above technical solution, the micropore volume of the catalyst is 0.10–0.30 cm³. 3 ·g -1The mesopore volume is 0.30–0.65 cm³. 3 ·g -1 Specific surface area is 300-650 m² 2 ·g -1 Preferably, the catalyst has a micropore volume of 0.11–0.22 cm³. 3 ·g -1 The mesopore volume is 0.40–0.65 cm³. 3 ·g -1 Specific surface area is 350-500 m² 2 ·g -1 .

[0016] The second aspect of the present invention provides a method for preparing the above-mentioned hydrogenation alkylation catalyst, comprising: impregnating a molecular sieve with an impregnation solution containing a metal component, and then subjecting it to drying, calcination, ammonium exchange, and reduction to obtain the hydrogenation alkylation catalyst.

[0017] In the above technical solution, preferably, the method for preparing the molecular sieve includes:

[0018] (a) A mixture A is obtained by contacting a silicon source, an aluminum source, an alkali source, water, a template agent, and a stabilizer;

[0019] (b) Crystallize mixture A to obtain the molecular sieve.

[0020] In the above technical solution, preferably, the silicon source mentioned in step (a) is one or more of tetraethyl orthosilicate, tetraethoxysilane, alkaline silica sol, fumed silica, sodium silicate, and silicic acid.

[0021] In the above technical solution, preferably, the aluminum source in step (a) is one or more of sodium aluminate, boehmite, aluminum isopropoxide, aluminum sulfate, and aluminum chloride.

[0022] In the above technical solution, preferably, the alkali source mentioned in step (a) is one or more of sodium hydroxide and potassium hydroxide.

[0023] In the above technical solution, preferably, the template agent mentioned in step (a) is one or more of hexamethyleneimine, piperidine, ethylenediamine, cyclohexylamine, and dimethylcyclohexylamine.

[0024] In the above technical solution, preferably, the stabilizer mentioned in step (a) is selected from at least one of carbonyl-nitroamide compounds, and the structural formula of the carbonyl-nitroamide compound is as follows: R1, R2, and R3 are each independently selected from hydrogen atoms or organic groups, wherein R1, R2, and R3 are each independently selected from hydrogen atoms, ethyl, cyclohexyl, piperidinyl, pyridinyl, pyrimidinyl, methylpiperidinyl, methylpyridinyl, or methylpyrimidinyl. More preferably, the stabilizer is selected from at least one of 4-piperidinecarboxamide, N-cyclohexylcarboxamide, N-ethylcarboxamide, 2-pyridinamide, and 6-methylnicotinamide.

[0025] In the above technical solution, preferably, in step (a), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source, water, template agent and stabilizer is 1:(0.01~0.10):(0.02~0.50):(8~25):(0.05~0.5):(0.01~0.30), and more preferably 1:(0.01~0.07):(0.05~0.30):(10~20):(0.1~0.5):(0.02~0.10).

[0026] In the above technical solution, preferably, the crystallization conditions in step (b) are dynamic crystallization under closed conditions, with a crystallization temperature of 90–190°C and a crystallization time of 20–120 hours. The dynamic crystallization is carried out under stirring conditions, preferably with a stirring speed of 10–50 rpm.

[0027] In the above technical solution, preferably, the crystallization treatment in step (b) can be followed by conventional post-processing steps in the art: separation, washing, drying, and calcination. The separation is performed by centrifugation, and the washing is done with deionized water until the pH of the separated solid is approximately 7.0–8.0. The drying conditions are 100–180°C for 5–20 hours. The calcination temperature is 450–600°C, the calcination time is 2–6 hours, and the calcination atmosphere is an oxygen-containing gas, such as air.

[0028] In the above technical solution, preferably, in the method for preparing the molecular sieve, the utilization rate of the raw material aluminum source is 91.0% to 99.0%, and more preferably 93.0% to 98.0%.

[0029] In the above technical solution, preferably, in the catalyst preparation method, the impregnation solution containing metal components can be a soluble metal salt, preferably a metal chloride.

[0030] In the above technical solution, preferably, in the catalyst preparation method, the impregnation method is preferably equal volume impregnation, the impregnation temperature is 20-60℃, and the impregnation time is 6-24 hours.

[0031] In the above technical solution, preferably, the drying conditions after impregnation in the catalyst preparation method are: drying temperature of 90-120℃ and drying time of 6-12h. The calcination conditions are an oxygen-containing atmosphere (e.g., air atmosphere), calcination temperature of 300-500℃, and calcination time of 2-5h. The ammonium exchange conditions are treatment with a 2%-10% ammonium salt solution at 20-70℃ for 1-5h, repeated 2-5 times. The ammonium salt is at least one of ammonium sulfate, ammonium acetate, or ammonium nitrate. During the ammonium exchange, the ammonium salt solution is added at a liquid-to-solid volume ratio of 10:1 to 3:1.

[0032] In the above technical solution, preferably, in the catalyst preparation method, the reducing atmosphere is a mixture of nitrogen and hydrogen, wherein the volume ratio of nitrogen to hydrogen is 9:1 to 7:3. The reduction temperature is preferably 250 to 450°C, and the reduction time is preferably 2 to 8 hours.

[0033] In the above technical solution, the hydrogenation alkylation catalyst can be in any physical form, such as powder, granules, or molded products, such as flakes, strips, or clover-shaped. These physical forms can be obtained in any manner conventionally known in the art, without particular limitation. When the hydrogenation alkylation catalyst is shaped as needed, the specific preparation method can be: impregnating a molecular sieve with an impregnation solution containing metal components, then mixing and shaping it with a binder, followed by drying, calcination, ammonium exchange, and reduction to obtain the hydrogenation alkylation catalyst. The binder can be at least one of alumina, silica, and titanium dioxide. The amount of binder added accounts for 10% to 40% of the molecular sieve mass.

[0034] The catalyst of this invention is particularly suitable for the hydrogenation alkylation of benzene to produce cyclohexylbenzene.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. The inventors have discovered through research that a hydrogenation alkylation catalyst using molecular sieves with specific skeletal aluminum content and distribution as the support and alkylation active component, and noble metals as the hydrogenation active component, in the benzene hydrogenation alkylation reaction, can improve the conversion rate of benzene and the selectivity of cyclohexylbenzene products under relatively low metal loading and relatively mild reaction conditions, and has good stability.

[0037] 2. This invention introduces a stabilizer during the preparation of molecular sieves to effectively limit and regulate the distribution of framework aluminum in the molecular sieves. After loading the metal, it can achieve efficient synergistic cooperation between the metal active center and the molecular sieve alkylation center, jointly improving the performance of the catalyst. In particular, it has good cyclohexylbenzene selectivity in the hydrogenation alkylation reaction of benzene. Attached Figure Description

[0038] Figure 1 The XRD patterns of the molecular sieves obtained in Example 1 and Comparative Example 1 of this invention are shown below.

[0039] Figure 2 The Al-NMR spectrum of the molecular sieve obtained in Example 1 of this invention;

[0040] Figure 3 The image shows the Al-NMR spectrum of the molecular sieve obtained in Comparative Example 1 of this invention. Detailed Implementation

[0041] To provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the present invention will be described in detail below with reference to specific embodiments. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0042] In this invention, the distribution of aluminum species in the molecular sieve is determined by analysis. 27 The Al MAS NMR results were obtained using a JEOL 500MHz (11.7T) spectrometer with a 3.2mm HX MAS NMR probe at a rotation speed of 18kHz. The spectrum was acquired at a resonance frequency of 130.3MHz. Chemical shifts were referenced to a 1mol / L Al(NO3)3 solution (δ = 0ppm). The values ​​of δ = 0ppm and 54ppm in the spectrum correspond to octahedral coordinated non-framework aluminum (Al2O3)2, respectively. [EF] ) and four-coordinated framework aluminum (Al [F] The characteristic peaks of ) can be used to determine the aluminum distribution at different tetrahedral sites by performing peak fitting calculations on the latter, where the Al distribution at δ = 50 ppm is determined. (50) Al corresponding to the 12MR supercage of molecular sieve F Distribution, Al deposition at δ = 56 ppm (Al (56) ) corresponds to Al in a sinusoidal channel [F] Distribution, Al deposition at δ = 61 ppm (Al (61) ) Corresponding to the Al on the outer surface of the 12MR semi-supercage [F] distributed.

[0043] In this invention, a Micromeritics ASAP-2000 physical adsorption instrument was used to determine the N2 adsorption-desorption isotherm at 77K. Before the test, the sample was degassed and vacuum-treated at 573K for 4h. The total pore volume and specific surface area were calculated using the BET equation, and the micropore volume was determined using the t-plot curve method. The difference between the total pore volume and the micropore volume is the mesopore volume.

[0044] In this invention, the SiO2 / Al2O3 molar ratio of the molecular sieve and the utilization rate of the raw material aluminum source are obtained by ICP testing and calculation, and are determined using a Varian 725-ES ICP-AES analyzer.

[0045]

Example 1

[0046] This embodiment is used to synthesize a hydrogenation alkylation catalyst, and the specific preparation process is as follows:

[0047] (1) Dissolve 11.3g sodium aluminate (Al2O3 45.0wt%) and 6.0g sodium hydroxide in 234.0g water. After stirring continuously until dissolved, add 24.8g hexamethyleneimine and 6.4g 4-piperidinecarboxamide. After stirring for 30min, add 208.3g tetraethoxysilane. The molar ratio of the reactants is tetraethoxysilane (SiO2): sodium aluminate (Al2O3): NaOH: water: hexamethyleneimine: stabilizer = 1:0.05:0.15:13:0.25:0.05. After stirring for another 30 minutes until the mixture is homogeneous, it is placed in a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 160°C and 30 rpm for 72 hours in a homogeneous reactor. The resulting mixture is then centrifuged, washed with deionized water to pH 7, dried in a 150°C oven for 8 hours, and calcined in air at 500°C for 5 hours to obtain molecular sieve M1.

[0048] (2) Take 1.0g of the M1 molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate the water absorption of 1.0g of molecular sieve to be 1.7mL. Add 17mL of 1.2mg / mL RuCl3 aqueous solution dropwise to 10g of the molecular sieve prepared in step (1), and use an oscillator to make the metal salt solution evenly distributed on the molecular sieve. After standing at 30℃ for 12h, add 3.0g of alumina and mix well. Knead and shape into strips, dry at 120℃ for 12h, and then calcine in air atmosphere at 350℃ for 3h. Treat with 5% ammonium acetate solution at 30℃ for 2h according to the liquid-to-solid volume ratio of 10:1, and exchange continuously 3 times. Then place in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 9:1, and reduce at 300℃ for 2h to obtain the target catalyst C1. In the catalyst, Ru accounts for 0.2% of the molecular sieve mass.

[0049] The XRD pattern of the prepared M1 molecular sieve is as follows: Figure 1 As shown.

[0050] The Al-NMR spectrum of the prepared M1 molecular sieve is as follows: Figure 2 As shown in Table 1, the distribution of aluminum species is shown in the table.

[0051] The utilization rate of the raw material aluminum source when preparing molecular sieve M1 is shown in Table 1.

[0052] The micropore volume of catalyst C1 was determined to be 0.15 cm³. 3 ·g -1 The mesopore volume is 0.59 cm³. 3 ·g -1 Specific surface area is 427 m² 2 ·g -1 .

[0053] The hydrogenation alkylation reaction of catalyst C1 was evaluated at a reaction temperature of 140 °C, a reaction pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0054]

Example 2

[0055] This embodiment is used to synthesize a hydrogenation alkylation catalyst, and the specific preparation process is as follows:

[0056] (1) Dissolve 9.2g sodium aluminate (Al2O3 45.0wt%) and 2.0g sodium hydroxide in 360.0g water and stir continuously until dissolved. Then add 70.1g hexamethyleneimine and 9.8g 2-pyridine amide. After stirring for 30min, add 208.3g tetraethoxysilane. The molar ratio of the reactants is tetraethoxysilane (SiO2): sodium aluminate (Al2O3): NaOH: water: hexamethyleneimine: stabilizer = 1:0.04:0.05:20:0.5:0.08. After stirring for another 30 minutes until the mixture is homogeneous, it is placed in a stainless steel reactor with a polytetrafluoroethylene liner and crystallized in a homogeneous reactor at 170°C and 20 rpm for 60 hours. The resulting mixture is then centrifuged, washed with deionized water to pH 7, dried in an oven at 130°C for 10 hours, and calcined in air at 550°C for 4 hours to obtain molecular sieve M2.

[0057] (2) Take 1.0g of the M2 molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate the water absorption of 1.0g of molecular sieve to be 1.7mL. Add 17mL of 1.5mg / mL PdCl2 aqueous solution dropwise to 10g of the molecular sieve obtained in step (1), and use an oscillator to make the metal salt solution evenly distributed on the molecular sieve. After standing at 20℃ for 16h, add 2.5g of alumina and mix well. Knead and shape into a clover shape, dry at 110℃ for 10h, and then calcine in air atmosphere at 300℃ for 4h. Treat with 7% ammonium sulfate solution at 20℃ for 1h according to the liquid-to-solid volume ratio of 8:1, and exchange 4 times continuously. Then place it in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 7:1, and reduce at 280℃ for 3h to obtain the target catalyst C2. In the catalyst, Pd accounts for 0.25% of the molecular sieve mass.

[0058] The XRD pattern of molecular sieve M2 indicates that it is MCM-22 molecular sieve.

[0059] The distribution of aluminum species obtained by Al-NMR testing and peak fitting of molecular sieve M2 is shown in Table 1.

[0060] The utilization rate of the raw material aluminum source when preparing molecular sieve M2 is shown in Table 1.

[0061] The micropore volume of catalyst C2 was determined to be 0.13 cm³. 3 ·g -1 The mesopore volume is 0.51 cm³. 3 ·g -1 Specific surface area is 410 m² 2 ·g -1 .

[0062] The catalyst C2 was evaluated during a hydrogenation alkylation reaction at a temperature of 140 °C, a pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0063]

Example 3

[0064] This embodiment is used to synthesize a hydrogenation alkylation catalyst, and the specific preparation process is as follows:

[0065] (1) Dissolve 6.8g sodium aluminate (Al2O3 45.0wt%) and 8.0g sodium hydroxide in 270.0g water. After stirring continuously until dissolved, add 17.0g piperidine and 4.1g 6-methylnicotinamide. After stirring for 30min, add 208.3g tetraethoxysilane. The molar ratio of the reactants is tetraethoxysilane (SiO2): sodium aluminate (Al2O3): NaOH: water: piperidine: stabilizer = 1:0.03:0.2:15:0.2:0.03. Continue stirring for 30min until uniformly mixed. Then, put it into a stainless steel reactor with a polytetrafluoroethylene liner and place it in a homogeneous reactor for crystallization at 150℃ and 25rpm for 96 hours. After that, centrifuge the obtained mixture, wash it with deionized water to pH 7, dry it in an oven at 140℃ for 9h, and calcine it in air at 550℃ for 6h to obtain molecular sieve M3.

[0066] (2) Take 1.0g of the M3 molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate that the water absorption of 1.0g of molecular sieve is 1.7mL. Add 17mL of 0.6mg / mL PtCl4 aqueous solution dropwise to 10g of the molecular sieve prepared in step (1). During this process, use an oscillator to ensure that the metal salt solution is evenly distributed on the molecular sieve. Let it stand at 40℃ for 10h, add 3.5g of alumina and mix well. Knead and shape into strips, dry at 100℃ for 10h, and then calcine in air at 400℃ for 2h. Treat with 8% ammonium acetate solution at 40℃ for 1h according to the liquid-to-solid volume ratio of 6:1, and exchange 4 times continuously. Then place it in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 8:1, and reduce at 300℃ for 3h to obtain the target catalyst C3. In the catalyst, Pt accounts for 0.1% of the molecular sieve mass.

[0067] The XRD pattern of molecular sieve M3 indicates that it is MCM-22 molecular sieve.

[0068] The distribution of aluminum species obtained by Al-NMR testing and peak fitting of molecular sieve M3 is shown in Table 1.

[0069] The utilization rate of the raw material aluminum source when preparing molecular sieve M3 is shown in Table 1.

[0070] The micropore volume of catalyst C3 was determined to be 0.12 cm³. 3 ·g -1 The mesopore volume is 0.47 cm³. 3 ·g -1 Specific surface area is 392m² 2 ·g -1 .

[0071] The catalyst C3 was evaluated during a hydrogenation alkylation reaction at a temperature of 140 °C, a pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0072]

Example 4

[0073] This embodiment is used to synthesize a hydrogenation alkylation catalyst, and the specific preparation process is as follows:

[0074] (1) Dissolve 5.8g of boehmite and 8.4g of potassium hydroxide in 216.0g of water and stir continuously until dissolved. Then add 24.8g of hexamethyleneimine and 3.7g of N-ethylformamide. After stirring for 30min, add 150.0g of silica sol. The molar ratio of the reactants is: silica sol (SiO2): boehmite (Al2O3): KOH: water: hexamethyleneimine: stabilizer = 1:0.05:0.15:12:0.25:0.05. Continue stirring for 30min until uniformly mixed. Then, put it into a stainless steel reactor with a polytetrafluoroethylene liner and place it in a homogeneous reactor for crystallization at 175℃ and 15rpm for 40 hours. After that, centrifuge the resulting mixture, wash it with deionized water to pH 7, dry it in an oven at 120℃ for 12h, and calcine it in air at 480℃ for 5h to obtain M4 molecular sieve.

[0075] (2) Take 1.0g of the M4 molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate that the water absorption of 1.0g of molecular sieve is 1.7mL. Add 17mL of 0.9mg / mL RuCl3 aqueous solution dropwise to 10g of the molecular sieve prepared in step (1). During this process, use an oscillator to ensure that the metal salt solution is evenly distributed on the molecular sieve. After standing at 30℃ for 10h, add 2.5g of alumina and mix well. Knead and shape into strips, dry at 120℃ for 8h, and then calcine in air at 450℃ for 2h. Treat with 9% ammonium acetate solution at 30℃ for 1h according to the liquid-to-solid volume ratio of 5:1, and repeat the treatment 4 times. Then place it in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 6:1, and reduce at 350℃ for 2h to obtain the target catalyst C4. In the catalyst, Ru accounts for 0.15% of the molecular sieve mass.

[0076] The XRD pattern of molecular sieve M4 indicates that it is MCM-22 molecular sieve.

[0077] The distribution of aluminum species obtained by Al-NMR testing and peak fitting of molecular sieve M4 is shown in Table 1.

[0078] The utilization rate of aluminum source in the preparation of molecular sieve M4 is shown in Table 1.

[0079] The micropore volume of catalyst C4 was determined to be 0.13 cm³. 3 ·g -1 The mesopore volume is 0.48 cm³. 3 ·g -1 Specific surface area is 404 m² 2 ·g -1 .

[0080] The hydrogenation alkylation reaction of catalyst C4 was evaluated at a reaction temperature of 140 °C, a reaction pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0081]

Example 5

[0082] This embodiment is used to synthesize a hydrogenation alkylation catalyst, and the specific preparation process is as follows:

[0083] (1) Dissolve 10.2g of aluminum isopropoxide and 6.0g of NaOH in 324.0g of water. After stirring continuously until dissolved, add 24.8g of hexamethyleneimine and 6.4g of N-cyclohexylformamide. After stirring for 30min, add 65.0g of silica. The molar ratio of the reactants is silica (SiO2): aluminum isopropoxide (Al2O3): NaOH: water: hexamethyleneimine: stabilizer = 1:0.05:0.2:18:0.25:0.05. Continue stirring for 30min until uniformly mixed. Then, put it into a stainless steel reactor with a polytetrafluoroethylene liner and place it in a homogeneous reactor for crystallization at 160℃ and 30rpm for 72 hours. After that, centrifuge the resulting mixture, wash it with deionized water to pH 7, and then dry it in an oven at 150℃ for 8h. Then, calcine it in air at 500℃ for 5h to obtain M5 molecular sieve.

[0084] (2) Take 1.0g of the M5 molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate that the water absorption of 1.0g of molecular sieve is 1.7mL. Add 17mL of 1.2mg / mL RuCl3 aqueous solution dropwise to 10g of the molecular sieve prepared in step (1). During this process, use an oscillator to ensure that the metal salt solution is evenly distributed on the molecular sieve. After standing at 30℃ for 12h, add 2g of silicon dioxide and mix well. Knead and shape into strips, dry at 120℃ for 12h, and then calcine in air at 350℃ for 3h. According to the liquid-to-solid volume ratio of 10:1, treat with 5% ammonium acetate solution at 30℃ for 2h, and exchange continuously 3 times. Then place in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 9:1, and calcine at 300℃ for 2h to obtain the target catalyst C5. In the catalyst, Ru accounts for 0.2% of the molecular sieve mass.

[0085] The XRD pattern of molecular sieve M5 indicates that it is MCM-22 molecular sieve.

[0086] The distribution of aluminum species obtained by Al-NMR testing and peak fitting of molecular sieve M5 is shown in Table 1.

[0087] The utilization rate of aluminum source in the preparation of molecular sieve M5 is shown in Table 1.

[0088] The micropore volume of catalyst C5 was determined to be 0.14 cm³. 3 ·g -1 The mesopore volume is 0.50 cm³. 3 ·g -1 Specific surface area is 415 m² 2 ·g -1 .

[0089] The hydrogenation alkylation reaction of catalyst C5 was evaluated at a reaction temperature of 140 °C, a reaction pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0090]

Example 6

[0091] This embodiment is used to synthesize a hydrogenation alkylation catalyst, and the specific preparation process is as follows:

[0092] (1) Dissolve 11.3g sodium aluminate (Al2O3 45.0wt%) and 6.0g sodium hydroxide in 234.0g water. After stirring continuously until dissolved, add 24.8g hexamethyleneimine and 6.4g 4-piperidinecarboxamide. After stirring for 30min, add 208.3g tetraethoxysilane. The molar ratio of the reactants is tetraethoxysilane (SiO2): sodium aluminate (Al2O3): NaOH: water: hexamethyleneimine: stabilizer = 1:0.05:0.15:13:0.25:0.05. After stirring for another 30 minutes until the mixture is homogeneous, it is placed in a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 160°C and 30 rpm for 72 hours in a homogeneous reactor. The resulting mixture is then centrifuged, washed with deionized water to pH 7, dried in a 150°C oven for 8 hours, and calcined in air at 500°C for 5 hours to obtain molecular sieve M6.

[0093] (2) Take 1.0g of the M6 ​​molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate that the water absorption of 1.0g of molecular sieve is 1.7mL. Add 17mL of 1.2mg / mL RuCl3 aqueous solution dropwise to 10g of the molecular sieve prepared in step (1). During this process, use an oscillator to ensure that the metal salt solution is evenly distributed on the molecular sieve. After standing for 12h, add 3g of titanium oxide and mix well. Knead and shape into strips, dry at 120℃ for 12h, and then calcine in air at 350℃ for 3h. Treat with 5% ammonium acetate solution at 30℃ for 2h according to the liquid-to-solid volume ratio of 10:1, and exchange continuously 3 times. Then place in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 9:1, and heat to 300℃ at a heating rate of 2℃ / min. After reduction for 2h, the target catalyst C6 is obtained. In the catalyst, Ru accounts for 0.25% of the molecular sieve mass.

[0094] The XRD pattern of molecular sieve M6 indicates that it is an MCM-22 molecular sieve. The distribution of aluminum species obtained from Al-NMR peak fitting of molecular sieve M6 is shown in Table 1.

[0095] The utilization rate of aluminum source in the preparation of molecular sieve M6 is shown in Table 1.

[0096] The micropore volume of catalyst C6 was determined to be 0.15 cm³. 3 ·g -1 The mesopore volume is 0.49 cm³. 3 ·g -1 Specific surface area is 418 m² 2 ·g -1 .

[0097] The catalyst C6 was evaluated during a hydrogenation alkylation reaction at a temperature of 140 °C, a pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0098] Comparative Example 1

[0099] Compared with Example 1, this comparative example did not add a stabilizer, but all other steps were the same. The specific process is as follows:

[0100] (1) Dissolve 11.3g of sodium aluminate (Al2O3 45.0wt%) and 6.0g of sodium hydroxide in 234.0g of water. After stirring continuously until dissolved, add 24.8g of hexamethyleneimine and stir for 30min. Then add 208.3g of tetraethoxysilane. The molar ratio of the reactants is tetraethoxysilane (SiO2): sodium aluminate (Al2O3): NaOH: water: hexamethyleneimine = 1:0.05:0.15:13:0.25. Continue stirring for 30min until homogeneous. Then, put it into a stainless steel reactor with a polytetrafluoroethylene liner and place it in a homogeneous reactor for crystallization at 160℃ and 30rpm for 72 hours. After that, centrifuge the resulting mixture, wash it with deionized water to pH 7, and then dry it in an oven at 150℃ for 8h. Then, calcine it in air at 500℃ for 5h to obtain D1 molecular sieve for later use.

[0101] (2) Take 1g of the D1 molecular sieve obtained in step (1), and continuously add deionized water until the molecular sieve is just saturated and moistened. Calculate that the water absorption of 1g of molecular sieve is 1.7mL. Add 17mL of 1.2mg / mL RuCl3 aqueous solution dropwise to 10g of the molecular sieve prepared in step (1). During this process, use an oscillator to ensure that the metal salt solution is evenly distributed on the molecular sieve. After standing at 30℃ for 12h, add 3g of alumina and mix well. Knead and shape into strips, dry at 120℃ for 12h, and then calcine in air at 350℃ for 3h. According to the liquid-to-solid volume ratio of 10:1, treat with 5% ammonium acetate solution at 30℃ for 2h, and exchange continuously 3 times. Then place in a tube furnace, introduce a mixed gas of nitrogen and hydrogen in a volume ratio of 9:1, and heat to 300℃ at a heating rate of 2℃ / min. After reduction for 2h, the target catalyst C7 is obtained. In the catalyst, Ru accounts for 0.2% of the molecular sieve mass.

[0102] The XRD pattern of the prepared D1 molecular sieve is as follows: Figure 1 As shown.

[0103] The Al-NMR spectrum of the prepared D1 molecular sieve is as follows: Figure 3 As shown in Table 1, the distribution of aluminum species obtained by peak fitting is shown in Table 1.

[0104] The utilization rate of the raw material aluminum source when preparing molecular sieve D1 is shown in Table 1.

[0105] The micropore volume of catalyst C7 was determined to be 0.12 cm³. 3 ·g -1 The mesopore volume is 0.46 cm³. 3 ·g -1 Specific surface area is 389m² 2 ·g -1 .

[0106] The hydrogenation alkylation reaction of catalyst C7 was evaluated at a reaction temperature of 140 °C, a reaction pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0107] Comparative Example 2

[0108] Compared with Example 1, this comparative example did not have metal loading, but all other steps were the same. The specific process is as follows:

[0109] (1) Dissolve 11.3g sodium aluminate (Al2O3 45.0wt%) and 6.0g sodium hydroxide in 234.0g water. After stirring continuously until dissolved, add 24.8g hexamethyleneimine and 6.4g 4-piperidinecarboxamide. After stirring for 30min, add 208.3g tetraethoxysilane. The molar ratio of the reactants is tetraethoxysilane (SiO2): sodium aluminate (Al2O3): NaOH: water: hexamethyleneimine: stabilizer = 1:0.05:0.15:13:0.25:0.05. After stirring for another 30 minutes until the mixture is homogeneous, it is placed in a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 160°C and 30 rpm for 72 hours in a homogeneous reactor. The resulting mixture is then centrifuged, washed with deionized water to pH 7, dried in a 150°C oven for 8 hours, and calcined in air at 500°C for 5 hours to obtain D2 molecular sieve.

[0110] (2) Take 10g of molecular sieve and add 3.0g of alumina to mix evenly, knead into strip shape, dry at 120℃ for 12h, and then calcine in air atmosphere at 350℃ for 3h; treat with ammonium acetate solution with mass concentration of 5% at 30℃ for 2h according to liquid-solid volume ratio of 10:1, and exchange continuously 3 times; then place in tube furnace, introduce mixed gas of nitrogen and hydrogen volume ratio of 9:1, reduce at 300℃ for 2h to obtain target catalyst C8.

[0111] The micropore volume of catalyst C8 was determined to be 0.16 cm³. 3 ·g -1 The mesopore volume is 0.60 cm³. 3 ·g -1 Specific surface area is 440m² 2 ·g -1 .

[0112] The C8 catalyst was evaluated during a hydrogenation alkylation reaction at a temperature of 140 °C, a pressure of 0.9 MPa, and a benzene mass hourly space velocity of 1 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5, and the results after 36 hours of reaction are shown in Table 2.

[0113] Table 1 shows the distribution of aluminum species, silicon-to-aluminum ratio, and utilization rate of the raw aluminum source in the molecular sieves obtained in each example.

[0114]

[0115] Table 2 shows the reaction results of applying the obtained catalysts to the hydrogenation alkylation of benzene to cyclohexylbenzene.

[0116]

[0117]

[0118] Single-cycle life test

[0119] The catalysts C1-C7 prepared in Examples 1-6 and Comparative Example 1 were tested for their single-pass lifetime in the benzene hydrogenation alkylation reaction under ultra-high benzene space velocity reaction conditions: reaction temperature 140°C, reaction pressure 0.9 MPa, and benzene mass hourly space velocity 8 h⁻¹. -1 The molar ratio of hydrogen to benzene was 0.5. The single-pass lifetime refers to the time elapsed from the start of the reaction until the conversion rate of benzene drops to 40% of the initial conversion rate. The test results are shown in Table 3.

[0120] Table 3

[0121] Catalyst number Single-trip lifespan, h C1 167 C2 151 C3 142 C4 158 C5 149 C6 150 C7 85

[0122] The embodiments described above are merely detailed descriptions of the technical solutions of the present invention, but the present invention is not limited to the above embodiments, that is, the present invention does not depend on the steps described in the above embodiments to be implemented. In summary, any improvements made to the present invention by those skilled in the art, including the substitution of the raw materials and additives described in the present invention, the selection of specific implementation methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A hydrogenation alkylation catalyst, said catalyst comprising a metal component and a molecular sieve, wherein the molecular sieve has an aluminum (Al) framework. [F] With non-frame aluminum Al [EF] The weight ratio is 5.0~15.0:1; the outer surface of the molecular sieve is semi-supercage with aluminum Al inside. (61) With aluminum skeleton Al [F] The weight ratio is 0.22~0.50:1; In the catalyst, the metal component is selected from at least one of Ru, Pd, and Pt; In the catalyst, the metal component accounts for 0.05% to 1.0% of the molecular sieve mass by mass fraction; The molecular sieve is MCM-22 molecular sieve.

2. The catalyst according to claim 1, characterized in that, Aluminum (Al) framework of molecular sieves [F] With non-frame aluminum Al [EF] The weight ratio is 7.0~11.0:

1.

3. The catalyst according to claim 1, characterized in that, Aluminum (Al) framework of molecular sieves [F] With non-frame aluminum Al [EF] The weight ratio is 7.0~10.0:

1.

4. The catalyst according to claim 1, characterized in that, The outer surface of the molecular sieve contains semi-supercage aluminum (Al). (61) With aluminum skeleton Al [F] The weight ratio is 0.22~0.42:

1.

5. The catalyst according to claim 1, characterized in that, The outer surface of the molecular sieve contains semi-supercage aluminum (Al). (61) With aluminum skeleton Al [F] The weight ratio is 0.25~0.30:

1.

6. The catalyst according to claim 1, characterized in that, In the catalyst, the metal component accounts for 0.10% to 0.30% of the molecular sieve mass by mass fraction.

7. The catalyst according to claim 1, characterized in that, The catalyst has a micropore volume of 0.10~0.30 cm³. 3 ·g -1 The mesopore volume is 0.30~0.65 cm³. 3 ·g -1 Specific surface area is 300~650 m² 2 ·g -1 .

8. The catalyst according to claim 7, characterized in that, The catalyst has a micropore volume of 0.11~0.22 cm³. 3 ·g -1 The mesopore volume is 0.40~0.65 cm³. 3 ·g -1 Specific surface area is 350~500 m² 2 ·g -1 .

9. A method for preparing the hydrogenation alkylation catalyst according to any one of claims 1-8, comprising: The molecular sieve is impregnated with an impregnation solution containing metal components, and then dried, calcined, exchanged with ammonium, and reduced to obtain the hydrogenation alkylation catalyst.

10. The preparation method according to claim 9, characterized in that, The method for preparing the molecular sieve includes: (a) A mixture A is obtained by contacting a silicon source, an aluminum source, an alkali source, water, a template agent, and a stabilizer; (b) Crystallize mixture A to obtain the molecular sieve.

11. The preparation method according to claim 10, characterized in that, The silicon source mentioned in step (a) is one or more of tetraethyl orthosilicate, tetraethoxysilane, alkaline silica sol, silica fume, sodium silicate, and silicic acid; and / or, the aluminum source is one or more of sodium aluminate, boehmite, aluminum isopropoxide, aluminum sulfate, and aluminum chloride; and / or, the alkali source is one or more of sodium hydroxide and potassium hydroxide; and / or, the template agent is one or more of hexamethyleneimine, piperidine, ethylenediamine, cyclohexylamine, and dimethylcyclohexylamine.

12. The preparation method according to claim 10, characterized in that, The stabilizer mentioned in step (a) is selected from at least one of carbonyl-nitroamide compounds, wherein the structural formula of the carbonyl-nitroamide compound is as follows: R1, R2 and R3 are each independently selected from hydrogen atoms or organic groups.

13. The preparation method according to claim 12, characterized in that, In the stabilizer described in step (a), R1, R2 and R3 are each independently selected from hydrogen atoms, ethyl, cyclohexyl, piperidinyl, pyridinyl, pyrimidinyl, methylpiperidinyl, methylpyridinyl or methylpyrimidinyl.

14. The preparation method according to claim 12, characterized in that, The stabilizer described in step (a) is selected from at least one of 4-piperidinecarboxamide, N-cyclohexylcarboxamide, N-ethylcarboxamide, 2-pyridinecarboxamide, and 6-methylnicotinamide.

15. The preparation method according to claim 10, characterized in that, In step (a), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source, water, template agent, and stabilizer is 1:(0.01~0.10):(0.02~0.50):(8~25):(0.05~0.5):(0.01~0.30).

16. The preparation method according to claim 15, characterized in that, In step (a), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source, water, template agent, and stabilizer is 1:(0.01~0.07):(0.05~0.30):(10~20):(0.1~0.5):(0.02~0.10).

17. The preparation method according to claim 10, characterized in that, The crystallization conditions described in step (b) are dynamic crystallization under closed conditions, with a crystallization temperature of 90~190 ℃ and a crystallization time of 20~120 hours.

18. The preparation method according to claim 10, characterized in that, In the preparation method of the molecular sieve, the utilization rate of the raw material aluminum source is 91.0%~99.0%.

19. The preparation method according to claim 18, characterized in that, In the preparation method of the molecular sieve, the utilization rate of the raw material aluminum source is 93.0%~98.0%.

20. The preparation method according to claim 9, characterized in that, In the catalyst preparation method, the impregnation method is equal-volume impregnation, the impregnation temperature is 20~60 ℃, and the impregnation time is 6~24 hours; and / or, the drying temperature is 90~120 ℃, and the drying time is 6~12 h; and / or, the calcination conditions are an oxygen-containing atmosphere, the calcination temperature is 300~500 ℃, and the calcination time is 2~5 h; and / or, the ammonium exchange conditions are treatment with an ammonium salt solution with a mass concentration of 2%~10% at 20~70 ℃ for 1~5 h, and continuous exchange 2~5 times; and / or, the reducing atmosphere is a mixture of nitrogen and hydrogen, wherein the volume ratio of nitrogen to hydrogen is 9:1~7:

3.

21. The preparation method according to claim 20, characterized in that, In the catalyst preparation method, the reduction temperature is 250~450 ℃ and the time is 2~8 h.

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